This invention relates to methods of manufacturing painted parts, and in particular to methods of manufacturing painted plastic parts adapted for use on motor vehicles such as air bag covers, side cladding, instrument panel cluster bezels, exterior bumpers, and the like.
Typically, plastic parts are painted after they are molded. The painting process requires elaborate facilities and consequently necessitates large expenses. For instance, significant square footage of a factory must be dedicated to a clean room environment for the spraying of paint and clear coat and for the baking and curing of paint on components, such as those components used in the automotive industry, such as body panels, air bag covers, instrument panels and the like. Moreover, solvent-based paints have in recent years raised significant environmental concerns because of the volatile organic components which are emitted into the air during the application of such solvent-based paints. As a result, the evaporation of such solvents must be strictly monitored to satisfy environmental and safety regulations.
In addition, automotive components, especially interior automotive components, are strictly scrutinized following the painting process in order to match or conform the automotive component to the styling and aesthetic requirements of the associated interior trim product. Painting such automotive components following the molding process, raises quality concerns with respect to the color, consistency, and thickness of each individual paint application.
U.S. Pat. No. 4,902,557, the Rohrbacher reference discloses a method and apparatus for manufacturing a thermoplastic polyolefin composite useful as an exterior auto or truck body part.
U.S. Pat. No. 4,769,100, the Short reference, teaches a method of applying a carrier film pre-printed with metallic paint to an automobile body panel in a vacuum forming process.
U.S. Pat. Nos. 4,952,351 and 5,466,412, the Parker patents, teach a method of manufacturing an air bag cover for an inflatable air bag system including a bondable film carrier, which is painted after the film carrier is molded.
However the prior art fails to provide a method of manufacturing a painted component wherein the step of painting the component after molding is eliminated and further where the component has the structural integrity both in terms of durability and strength to support varying applications.
An object of the present invention is to provide a method for manufacturing a painted component while addressing paint quality issues such as: drips, runs, spits, dry spray, light coverage, gloss, color match, contamination and paint adhesion.
Another object of the present invention is to provide a method for manufacturing a painted component and reducing molding scrap due to splay, flow marks and minor surface imperfections which can be completely covered.
Yet still another object of the present invention is to provide a method of manufacturing a painted component, such as a composite air bag cover, side cladding, and the like, wherein the components have increased durability.
In carrying out the above objects and other objects of the present invention a method is provided for manufacturing a painted plastic component. The method includes the steps of providing a film sheet having top and bottom surfaces; vacuum molding the film sheet and the mold cavity to obtain a pre-form; placing the pre-form in a mold cavity of an injection mold having a shape defining the desired plastic component; and injecting a thermoplastic elastomer into the mold cavity of the injection mold to generate a structural carrier for the pre-form, the generation of the structural carrier creating sufficient pressure and heat to bond the structural carrier to the bottom surface of the pre-form to form the molded laminate component.
Further in carrying out the above objects and other objects of the present invention, a method is provided for manufacturing a molded laminate automotive component. The method includes the steps of inserting a film sheet into a vacuum forming station to form the film sheet into a predetermined automotive component shape to create a formed film sheet having top and bottom surfaces, placing the formed film sheet in a mold cavity of an injection mold having a shape defining the automotive component, and injecting a thermoplastic elastomer into the mold cavity of the injection mold, such that the thermoplastic elastomer is in mating contact with the bottom surface of the formed film sheet, to generate a structural carrier for the formed film sheet, the generation of the structural carrier creating sufficient pressure and heat to bond the structural carrier to the bottom surface of the formed film sheet to form the molded laminate automotive component.
The above objects and other objects, features and advantages of the present invention are readily apparent from the following detailed description of the best mode for carrying out the invention when taken in connection with the accompanying drawings.